Fuel control system



July 8, 1941. w. A. RAY

FUEL CONTROL SYSTEM 2 Sheets-Sheet 1 Filed Aug. 29, 1938 L IN VENTOR.

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ATTORNEY July 8, 1941. w. A. RAY

FUEL cbnTRoL SYSTEM Filed Aug. 29, 1938 2 Sheets-Sheet 2 M 0 5 r0 2 J 4 l y/ U.

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Patented July 8,. 1941 "UNITED STATES PATENT OFFICE 2,243,306 FUEL CONTROL SYSTEM William A. Ray, Glendale, Calif. Application August 29, 1938, Serial No. 227,258

' (o1. ass-so) 3 Claims.

My present invention relates to the control of heating systems which employ fluid fuel, such as gas.

An object of my invention is the provision, in such a heating system, of means for controlling fuel flow to'a main burner and a source of thermoelectrically generated energy for operating said means.

A further object of my invention is the provision of fluid fuel consuming thermoelectric generating means for energizing a valve controlling fuel flow to a main burner and disposed in the vicinity of and exterior to a heating device, such as a gas consuming furnace.

1 My present invention, while not so limited, has particular utility in connection with. the control of furnaces of the conversion type which were originally designed for the burning of coal or fuel oil and which have been converted to the use of gaseousfuel. Within such a furnace very high temperatures may exist in the region of the burner, occasioned mainly by the arrangement of refractory materials near the burner for concentrating and conserving the heat generated thereby, with the result that-it is impractical to utilize certain devices in the region of such a burner.

A particular object of my invention is the provision of a novel conversion furnace control system including thermoelectric valve and disposed in the vicinity of and exterior to said furnace, the supply of fuel to said ther moelectric generating means being controlled by a safety valve responsive to the'presence of flame at a pilot burner associated with said main I burner. Q

My invention resides mainly in the novel com-.

bination and arrangement of the devices of the controlling system.

Other objects and advantages of my invention will be found in the description, the drawings and the appended claims.

For a complete understanding of the invention, reference may be had to the following detailed. description and accompanying drawings, in

which- Figure 1 is a more or less diagrammatic view of apparatus embodying my invention;

Figure 2 is a sectional view of the pilot valve shownin Fig. 1; and

Figure 3 is a section taken on the line 33 Referring more particularly to Fig, 1

conduit connected to the input of a fluid presgenerating means for energizing the main burner control of the drawings, the numeral II denotes a fuel supply sure operated main valve generally indicated by the numeral I2 and comprising a body I3, a casing I4 divided into upper and 1ower.compartments I5 and I6, respectively, by a diaphragm member I1, which member is operatively connected by a stem I8 to a valve member I9 to control fluid flow through the main valve. An electrically operated pilot valve 20, mounted on the casing I4, controls the operation of the main valve I2, in' a manner well known in the art, by the application of fluid pressure to the compartments I5 and I6 through conduits 2|, 22 and 23 and an aperture 24 (shown in Fig. 2) provided in an upper wall of the casing Id. The main valve shown is of the type wherein both compartments I5 and I6 are equally subjected to the fluid fuel pressure to close the valve. To open the valve, the upper compartment I5 is vented through a conduit 46 and vent 41, while maintaining the pressure in the lower compartment I6.

A compression spring 25 normally urges the valve member I9 to closed position. A lever 26 for operating a furnace damper or the like is' shown pivotally mounted on the casing I l and is operable through a rod 21 by movement of the diaphragm member I1.

Connected to the output of the main valve I2 by. means of a conduit 28 is a main burner 29 positioned in a heating device or furnace 30 having a wall 3|. Connected to the conduit II, ahead of the main valve I2, is a safety valve 32 controlling gaseous fuel flow through a conduit 33 to a pilot burner 34 and, also, through a conduit 35 to gas consuming thermoelectric generating devices 36.

These devices 36 are fully described in the copending application of William R. Ray, Serial No. 225,075, filed August 15, 1938, and comprise a series of thermocouple elements 31 heated by gas flames 38 issuing between said couple elements. The electrical output of the devices "36 is connected by wires 39 through a limit control or thermostat 40 to terminals 4| of the pilot valve 20.

The safety valve type, an example of which is disclosed in the patent to Karrer, No. 2,097,838. As the type name implies, this safety valve must be reset or opened manually, as by upward movement of a reset button 42, permitting flow of gas to the pilot burner 34, which upon ignition heats a thermocouple 43 which is electrically connected by means of a tubular conductor 44 and an enclosed' insulated wire 45 to an electromagnetic 32 is of the manual reset I deyice contained within the upper portion of the safety valve 32. The current generated by the heated thermocouple 43 serves to energize the core of the electromagnetic device to magnetically hold an armature in contact with the core, which armature is connected to the valve member and so is moved into contact with the core when the valve is reset, as described. above. The safety valve 32 is thus held in open position as long as the pilot burner 34 is lighted. Upon extinction of the pilot burner flame, the armature is released and drops, closing the valve. Current generated by the thermocouple is insuilicient to attract the armature from its released position and so it must be manually reset" to again open the valve.

In Fig. l, the valves l2 and 32 are closed, and for this reason flames 35, 45 and 49 are shown in broken lines as they would appear when the valves were open and the gas ignited,

In Figs. 2 and 3, the pilot valve 20 is shown in detail. The general structure of this device is shown and described in my copending application Serial No. 222,673, flied August 2, 1938.

Supported by the upper wall of a housing 50 is a bodymember II in which are threadedly'secured hollow jet or valve port members 52 and 53, adapted to be locked in position after adjustment by the packing nuts 54 and 55. Secured to the body member 5i, as by screws 55, is an apertured plate member 51 to which in turn is secured one arm. portion of a U-shaped core member 55, as by screws 59. Surrounding the other arm portion of the core member 58 is an energizing coil member 50, leads of which are brought to the terminals 4|, insulatingly mounted in the side wall of the housing 50. Cooperable with the jets 52 and 53 to control fluid flow therethrough is an armature member 52 fulcrumed on an edge 53 of the core member 55.

In the normal or unenergized condition of the core 55, the upper end portion of the armature 52 isurged by a compression spring 54 into contact with the jet 53, closing fluid flow therethrough. When the core 53 is energized, the

'lower end portion of the armature is attracted by pole 55, moving the upper end portion of the armature intopontact with the jet 52 and simultaneously opening jet 53. The movement of the armature in its attraction is limited by the jet 52, as is .shown in the broken line position ofthe armature, so that the lower end portion of the armature is prevented from contacting the 2,919 55. Thus, possibility of magnetic "sticking is avoided.

Movement of the armature between the jets Assuming that the main valve I2 and the safety valve 22 are closed, with resultant extinction of the main burner 29, pilot burner 34 and the thermoelectric generating devices 36, to initiate operation 01'. the system the reset button 42 is moved upwardly, opening valve 32. While maintaining button 42 in its depressed position, the gas now flowing at the pilot burner 34 and the thermoelectric generating devices 36 is ignited. As soon as the heated thermocouple 43 generates suflicient current to hold the valve 32 open, the button 42 may be released.

If the thermostat 40 is now in heat demand condition, the electric circuit through the thermoelectric device 35, the thermostat 40 and the energizing coil of the pilot valve 20 will be complete with the result that the armature 62 will move to open jet 53 and close jet 52. Fluid pressure that existed in the upper diaphragm compartment i 5 is relieved bythe venting of the compressed fluid through conduit 48 to the vent 41, where it is ignited by the pilot burner. Jet 52 being closed, the fluid pressure applied to the lower compartment l6 may now force the diaphragm member I! upward against the bias of spring 25 to open the main valve. When rise of temperature causes the thermostat to operate to open the pilot valve electrical circuit, the armature -52 is moved by the spring 84 to its original position as shown, permitting the fluid fuel pressure in the upper .and lower diaphragm .52 and 53 may be adjusted to as little as 0.004

inch and the clearance between the pole 55 and the lower end portion of the armature in its attracted position may be as little as 0.002 inch. Lateral movement of the armature is prevented by'a retaining member 55.

Passageways 51,15 and 59 permit fluid communication between the hollow jet member 52 and the conduit 23. And, likewise, passageways l0 and II permit communication between the hollow iet member 53 and the vent conduit 45. The end portions of the jet members 52 and 53 with which the armature cooperates may be made as small as 0.030 inch in diameter. On account oi the small surface area of these jets, the contact pressure ofthe armature on them may be great and sumcient to form gas-tight junctions,

compartments I 5 and i6 to become equalized, spring 25 then moving the valve member l9 to closed position.

ln case of accidental extinction of the pilot burner 34, the valve 32 closes, extinguishing the thermoelectric generating devices 35. On cooling 01 these devices, current ceases to be generated by them with the result that the main valve is closed as described above.

While I have shown two thermoelectric generating devices 35 connected in series, it is obvious that one or more of such devices, connected either in series or in parallel, may be employed depending upon the characteristics and requirements of the electrical circuit.

While I have shown a thermoelectrically energized manual reset safety valve, it is obvious that other well known forms of pilot burner safety valves, such as, for example, employ expansion rods, may be substituted.

An apparent advantageof the system of my D .present invention resides in thefact that no external source of electric power is required for operation of the main valve, with consequent elimination of additional wiring, possible fire hazard, and interruptions occasioned by electrical power failure.

It will be-seen that I have provided a novel, safe and efllcient control syste which, while it has particular utility in connection with furnaces of the "convension type, is obviously not so limited, and may be as well employed in the control of other gas consuming devices.

It will be readily apparent that changes may be made in the construction and arrangement of the parts and I am therefore to be limited only by the scope of the appended claims.

I claim as. my inventio 1. In a heating control system, in combination, a conversion furnace, a main burner-in said furnace, a conduit connecting said burner to a supply of fluid fuel, an electrically controlled valve.

controlling fuel flow to said main burner, a'pilot burner for said main burner, a fluid fuel consuming thermoelectric generatingdevice for energizing said electrically controlled valve and disposed adjacent and exterior to said furnace, said generating device comprising a plurality of pairs of relatively short thermocouple elements, and a second valve controlling fuel flow to said pilot burner and to said thermoelectric generating device and connected to said conduit ahead of said electrically operated valve.

2. In a heating control system, in combination, a conversion furnace, a main burnerin said furnace, a conduit connecting said main burner to a supply of fluid fuel, a first electrically controlled main valve for controlling fuel flow to said main burner, a pilot burner for said main burner,

a fluid fuel consuming thermoelectric generating device for energizing said first valve and disposed in the vicinity of and exterior to said furnace, said generating device comprising a plurality of pairs of relatively short thermocouple elements,

ciated with said pilot burner and heated thereby for holding said second valve in open position when it is brought to that position manually.

3. In a heating control system, in combination, a space to be heated, a conversion furnace for heating said space, a main burner in said furnace, a pilot burner for said main burner, a fluidpressure operated main valve controlling fuel supply through said conduit to said main burner, an electrically operated pilot valve for controlling said main valve, a fluid fuel consuming thermoelectric generating device for energizing said pilot valve and disposed in the vicinity of and exterior to said furnace, said generating device comprising a plurality of pairs of relatively short thermocouple elements, a temperature responsive device in said space and controlling said pilot valve, an electrically opertaed manual reset safety valve controlling fuel flow to said pilot burner and to said thermoelectric generating de- WILLIAM A. RAY. 

